Arylation of olefins

ABSTRACT

Reactions of nitro-aromatic compounds with olefins and diolefins is disclosed. When a nitro-aromatic is reacted with an olefin, the product is a vinyl-aromatic; for example, nitrobenzene and ethylene yields styrene. When a nitro-aromatic is reacted with a diolefin, the product is a fused ring, polycyclic aromatic; for example, nitrobenzene and butadiene yields naphthalene.

United States Patent 1151 3,691,243 Fields et al. 1 Sept. 12, 1972 [54]ARYLATION OF OLEFINS [56] References Cited [72] Inventors: Ellis K.Fields, River Forest; Allen I. UNTED STATES PATENTS Feinstein, Wheaten,both of ill. 3 527 794 9/1970 H k 60,669 c 1 Assignee= Standard CompanyChicago 3 574 777 4/1971 Hick ..260 669 111. 7 [22] Filed: Aug 14 1970Primary Examiner-Curtis R. Davis Attorney-Arthur G. Gelkins, Thomas L.Trinley and pp 63,928 William T. McClain 52 us. c1. ..26o/669 R, 260/621R, 260/645, [571 ABSTRACT 260/669 Q 260/671 A Reactions ofnitro-aromatic compounds with olefins [51] Int. Cl ..C07c 15/10 anddiolefins is disclosed when a nitro-aromatic is Field of Search 669 Q671 A, reacted with an olefin, the product is a vinyl-aromatic;

for example, nitrobenzene and ethylene yields styrene.

When a nitro-aromatic is reacted with a diolefin, the

product is a fused ring, polycyclic aromatic; for exam- ARYLATION FOLEFINS This invention relates to a new method for arylating certainclasses of monoand di-olefms. The reactions of this invention arerepresented by the following general equations:

CONJUGATED DlOLEFlN REACTION SCHEME For the monoolefinic reactions asrepresented in reaction scheme No. 1 above, with respect to thenitroaromatic compound the Ar group is a carbocyclic or hetrocycliccompound which is aromatic in character; X is a substituent such asalkyl for example, methyl, ethyl, propyl, and butyl; and iso-,secondary-and tertiary-alkyls such as isopropyl, t-butyl; halogenatedalkyl such as trichloromethyl and trifluoromethyl; halo, such as fluoro,chloro, bromo, and iodo; hydroxy and alkoxy; amino and monoalkylaminoand dialkylamine; mercapto and alkylthio; cyano, carboxy and estergroups; dicarboxylic acid anhydride groups; and acylamido groups; pbeing an integer from Oto 4; and wherein q is an integer from 1 to 3.The Ar group may be an aromatic carbocyclic radical such as benzene,fused carbocyclic compound, or a polyphenyl compound. The fusedcarbocyclic compounds having up to four rings are useful; preferred arethose having two or three rings with up to 14 carbon ring-atoms. Suchfused aromatic carbocyclic compounds include naphthalene, anthracene,phenanthrene, pyrene, chrysene, and rubrene. Polyphenyl structuresuseful are those from bi-phenyl and terphenyl. Heterocyclic compoundsproviding the nucleus for the nitro-compound or the co-reactant may bepolycyclic or monocyclic. The hetero atoms are selected from oxygen,nitrogen and sulfur. The hetero rings of both the monocyclic andpolycyclic types are 5- or 6-membered and are aromatic in character,i.e. the hetero-rings are characterized as a closed, conjugated system.Conjugated in the sense that 11 electrons can be found at alternatepositions around the ring either as the 11' electrons of the multiplebonds or the unshared electron pairs of the hetero atom. This structuralrequirement for aromaticity is well known to chemists and has beenelucidated by Fieser and Royals, among others.

The aromatic polycyclic heterocycles providing nuclei for the presentinvention are further characterized as being limited to two-three rings,each ring being fused to at least one other. While most of the usefulpolycyclic heterocycles consist of a single heteroring fused to 1-2benzene nuclei, compounds such as 1,8-napthyridine having all theirrings heterocyclic undergo the reaction. This is so, I have discovered,

because aromaticity regardless of the nature of the ring atoms-importsthe required stability. Exemplary of the useful polycyclic heterocyclesare the nitrogen-containing quinoline, acridine, phenanthridine,benzopyrrole, dibenzopyrrole, benzimidazole, benzoxazole napthyridine;the oxygen-containing benzofuran, dibenzofuran and xanthene; thesulfur-containing benzothiophene, dibenzothiophene, dibenzothiophene andbenzothiazole.

Useful aromatic monocyclic heterocycles include mono-hetero compounds asfuran, thiophene, pyrrole, N-methyl pyrrole and yrpidine; and suchall-nitrogen, aromatic polyazines as pyridazine, pyrazine, pryimidineand 1,3,5-triazine.

Additional examples of aromatic nitro compounds are nitrobenzene,p-nitrotoluene, 2- and nitronaphthalene, nitroanthracene,nitrophenanthrene, nitropyrene, nitroacenaphthene; 2-, 3-, and 4-chloronitrobenzene; 2-, 3-, and 4-fluoronitrobenzene; 2-, 3- and4-bromonitrobenzene; m-and pdinitrobenzene; 1,3,5-trinitrobenzene; 3-,4-nitro-oxylene; pand m-nitrobenzoic acid; methyl pand mnitro-benzoate;3- and 4-nitrobenzonitrile; 3- and 4- nitrobenzotrifluoride; 3- and4-nitrophenol; 3- and 4- nitroanisole; and 1,5-dinitronaphthalene, aswell as nitroquinolines such as S-nitroquinoline and 8- nitroquinoline.

Again with reference to scheme No. 1, the R groups substituting themonoolifinic structure may be hydrogen or the same or different alkyl,aryl, cycloalkyl, or heterocyclic radicals. Exemplary of thesemonoolefins are ethylene, propylene, isobutylene, styrene,a-methylstyrene, p-methylstyrene, p-dimethylstyrene, indene,2-vinylpyridine, 2-vinyl naphthalene, 3-vinyl-pyridine, 4-vinylpyridine,acrylonitrile, and vinyl acetate. It is to be noted that one of theolefinic carbon atoms must be substituted with a hydrogen atom.

Products from the olefinic reactions are useful as monomers forpolymerization to polymers for casting, molding, and films, and asintermediates for dyes, pharmaceuticals, and pesticides.

With reference to reaction scheme N0. 2, the fore going description ofthe aromatic nitro compound is applicable with the following exceptions:First, the compounds have only a single nitro substituent, and second,

whereas the X substituents may be substituted on any position of thecompound in the monoolefinic reactions, where diolefinic reactions arebeing run, at least one ring position ortho to the nitro group mustremain unsubstituted, i.e.--there must be an ortho hydrogen atom.

The conjugated diolefins of the present invention have the followinggeneral formula R1 R2 Ra R4 wherein the R groups are aliphatic,saturated hydrocarbons, containing up to 4 carbon atoms. Exemplary ofsuch compounds are isoprene, 2,3-dimethyl butadene, Z-methyl 3ethylbutadiene. The products of the diolefinic reactions are useful asfeedstocks for further oxidation to mono and carboxylic acids which inturn are useful components in plasticizers, polyesters, and

polyamides. The reaction conditions for the process of this inventionare as follows: the temperature is broadly 450-700C, preferably600-650C; the molar ratio of olefin to nitro compound is broadly 1:1 to50:1, preferably 2:1 to :1; reaction time may vary between 0.1 second to10 minutes; the reaction is most suitably conducted in the presence ofan inert gas such as nitrogen.

The following examples will illustrate the practice of the invention.Such examples are illustrative only and in no way do we intend to implythat they are co-extensive with the scope of this invention. Productswere isolated by fractional distillation in vacuo and/orcrystallization, and identified by boiling point, melting point,infrared and mass spectrometry, and by gas chromatography, by comparisonof retention times with those of authentic samples.

Example 1 Nitrobenzene, 12.3g. (0.1 mole), was passed through a Vycortube containing Vycor chips, heated in an electric furnace at 600 C,together with ethylene, (0.25 mole) flowing at 40 cc/min. Contact timewas 12.5 seconds. The condensate, 7.55g., was distilled at 30 mm.pressure to obtain 2.52g. (24.1 percent) styrene and 3.15g. (33.4percent) phenol.

Example 2 The reaction of Example 1 was repeated with ethylene (0.5mole) flowing at 80 cc/min. and a contact time of 16 seconds. The yieldof styrene was 28.4 percent and phenol, 14.6 percent.

Example 3 4-Fluoronitrobenzene, 14,1g. (0.1 mole), was passed through aVycor tube containing Vycor chips, heated at 600 C, together withethylene (0.3 mole) flowing at 40 cc/min.; contact time was 12.2seconds. The condensate, 8.3g., was distilled at 30 mm. to obtain 1.46g.(12 percent) 4-fluorostyrene and 0.78g. (7 percent) 4- fluorophenol.

Example 4 4-Chloronitrobenzene, 15.85g. (0.1 mole) was passed through aVycor tube containing Vycor chips, at 600 C together with ethylene (0.4mole) flowing at 50 cc/min.; contact time was 15.5 seconds. Thecondensate, 11.8g, was distilled at 30 mm. to obtain 2.2lg. (16 percent)4-chlorostyrene and 0.77g. (6 1 percent) pchlorophenol.

Example 5 Example 6 m-Nitrobenzotrifluoride, 8.55g. (0.05 mole), waspassed through a Vycor tube containing Vycor chips, at

600 C together with ethylene (0.5 mole) flowing at 60 cc/min.; contacttime was 11.3 seconds. The condensate, 6.08g., was analyzed by gaschromatography and mass spectrometry; it contained 1.89g. (22 percent)of 3-vinylbenzotrifluoride and 0.73g. (9 percent) of 3-hydroxybenzotrifluoride.

Example 7 l-Nitronaphthalene, 8.65g. (0.05 mole) was passed through aVycor tube containing Vycor chips, at 600 C together with ethylene (0.5mole) flowing at 60 cc/min.; contact time was 15 seconds. Thecondensate, 4.1g., was distilled at 2 mm. to recover 1.34g. (17.4percent) l-vinylnaphthalene. From the distillation residue, bycrystallization from methanol, was obtained 0.72g. (10percent)a-naphthol.

Example 8 Example 9 A mixture of 2.78g. (0.02 mole) of 4-nitrophenol and10.4g. (01 mole) of styrene was passed through a Vycor tube containingVycor chips, at 600 C under nitrogen flowing at 20 cc/min.; contact timewas 21.8 seconds. The condensate was distilled in vacuo to recover 7.4g.of styrene; analysis of the residue showed 1.29g. (33 percent) of4-hydroxyphenylstilbene and 0.64g. 16 percent) of 4-hydroxyphenylstyrene.

Example 10 A mixture of 6.15g. (0.05 mole) of nitrobenzene and 59g. (0.5mole)a-methylstyrene was passed through a Vycor tube containing Vycorchips, at 600C under nitrogen flowing at 20 cc/min.; contact time was12.5 seconds. The pyrolysate, 61.7g., was distilled in vacuo to recover43.4g. of a-methylstyrene; the residue (14.4g.) analyzed for 3.6g. (37percent) of a-methylstilbene and 3.4g. (35 percent) ofisopropenylbiphenyl.

Example 1 l A mixture of 8.65g. (0.05 mole) of 5-nitroquinoline and23.6g. (0.2 mole) of a-methylstyrene was passed through a Vycor tubecontaining Vycor chips, at 600 C under nitrogen flowing at 20 cc/min.;contact time, 11.4 seconds. The condensate, 27.8g., was distilled invacuo to recover 16.4g. of a-methylstyrene. The residue analyzed for 2.21 g. (18 percent) of l-phenyl-lmethyl-2- (S-quinolyl) ethylene and1.72g. (14 per cent) of 5-(isopropenylphenyl) quinoline.

Example 12 A mixture of 6.15g. (0.05 mole) of nitrobenzene and 58g. (0.5mole) of indene was passed through a Vycor tube containing Vycor chips,at 600 C under nitrogen flowing at cc/min.; contact time, 20 seconds.The condensate was distilled to recover 362g. of indene; the residue,13.6g., contained 4.53g. (47.3 percent) of phenylindene.

Example 13 A mixture of 2.46g. (0.02 mole) of nitrobenzene and 10.5g.(0.1 mole) of 4-vinylpyridine was passed through a Vycor tube containingVycor chips, at 600 C with nitrogens flowing at 20 cc/min.; contact timewas 9.5 seconds. The condensate was distilled to recover 6.7g. of4-vinylpyridine; the residue, 4.5g., contained 1.48g. (41 percent) of4-stilbazole by gas chromatographic analysis.

Example 14 A solution of p-nitrotoluene (6.86g., 0.05 mole) and isoprene(50 vol., 0.5 mole) was pyrolyzed at 600 C through a Vycor tube filledwith Vycor chips. The reaction was carried out under pure dry nitrogenwith a flow rate of 20cc/minute. The contact time was 11.2 seconds. Thevapors were condensed in a flask at 0 C, and the condensate wasdistilled (3690 C) to recover unreacted material. The residue obtainedafter distillation (21.5g.) was analyzed by gas chromatography. Theyield of Z-methylnaphthalene was 4.7 percent and dimethylnaphthalenes(50:50 mixture of the 2, 6 and 2, 7 isomers) was 15.0 percent.

Example 15 A solution of 4-nitro-o-xylene (7.55g., 0.05 mole) andisoprene (50 ml, 0.5 mole) was pyrolyzed at 600 C Example 16 A solutionof p-nitrotoluene (6.86g., 0.05 mole) and 2,3-dimethylbutadiene (56.4ml, 0.5 mole) was pyrolyzed at 600 C through a Vycor tube under theconditions described above. The contact time was 12.3 seconds. Thereaction mixture was distilled (6085 C) to give a distillate (18.2 g.)and a residue at C of 21.4g. The residue was analyzed by massspectrometry and gas chromatography, yielding 26.8 percent toluene, 20.0percent xylene, 2.4 percent 2,6-

dimethylnaphthalene, l .2 percent 2,7-dimethy1- naphthalene and 14.0percent 2,3,6-trimethylnaphthalene.

Having described our invention, what we claim is:

l. A process comprising reacting ethene with nitrobenzene in an inertatmosphere at a temperature between 450 C to about 700 C for asufficient time for reaction to occur, said co-reactants being presentin amounts such that the molar ratio of ethene to nitrobenzene is about1:1 to about 50: l.

